How the Interaction Map Works

The Process Interaction Map is a graphical display of the correlations between
process variables. The strength of the correlation is shown by the strength of the color
on the chart. Both positive (red) and negative (blue) correlations are shown.

Sort by strength of correlation, and you can immediately see which process variables have
the strongest influence.

Unit operation assessments on Process Interaction Map.
The Process Interaction Map will now show the correlations between loop Process Variables and Unit Operation Assessments. These are the OPC inputs you have assigned for a unit operation's energy cost, material cost, quality, reliability or throughput.

Find the Root Cause

Time-Shift Shows Cause and Effect

Process Interaction Map excels at finding the root cause of interaction problems. You can
quickly identify root causes by looking for the strongest colors, furthest to the right.

On the Interaction Map, left and right represent the time axis. Strong colors on the left
show likely "effects", because these variables lag behind the reference loop.
Strong colors on the right are leading indicators, so these are likely causes.

Fix One, Solve Many

Quite often, the root cause is found upstream, often in the utilities area of the plant.
When you identify the single root cause of the problem, you often stabilize many parts of
the downstream process.

Quantify the Impact of Improvements

When you make an improvement to the process and controls, there is a "ripple
effect" of benefits. Quite often, the major economic savings occurs downstream, away
from the loop you tuned. To document the true value, you need to know where to look.

The Process Interaction Map makes it easy for you to identify affected control loops.
Solving a level control problem might actual be reducing your energy costs! You just need
to know where to look.

Solve Interacting Loop Problems

Some common types of interacting loops include:

Cascade Controls

Ratio Controls

Feedforward Controls

Recycle Streams

Heat Integration

Upstream or Downstream Process

Unless you know where to look, you can't solve these problems. The Process Interaction
Map points you in the right direction, so you always know which loops have the strongest
interactions.

Incredible Process Insights

Process engineers are often the most impressed with the Process Interaction Map. This is
because it offers incredible insights into the performance of the process. You can answer
questions like these:

Which process setpoints have an impact on finished product quality?

What is the effect of product mix on energy consumption?

When we change raw materials, how long before the finishing unit is affected?

Does the reactor temperature affect the product quality? By how much?

What is the greatest source of process variability?

Aberdeen Group published "Operational Excellence in the Process Industries", which
included a case study on Interaction Maps. Interaction Mapping Saves $1 Million:
Read the Case Study.

Get the Big Picture with Interaction Hot Spots

Interaction Hot Spots graphically highlight interactions from across the plant. Using
this tool, engineers can quickly find the root cause of process interactions. Upsets to
quality, energy and shut downs are easily seen.

Interaction Hot Spots is also very useful as a tool for developing the scope of MPC projects.